Molecular biologist Dr Elizabeth Blackburn says she was following her nose when she and two colleagues found a key to staving off the ravages of aging.

Blackburn, who was born in Hobart and studied in Melbourne, shares this year's Nobel Prize in Medicine with fellow researchers Dr Carol Greider and British-born Dr Jack Szostak.

Their research on telomeres, the ends of chromosomes, has been praised as holding the promise of growing less frail with time or preventing the spread of cancer.

"It sort of translates into a fountain of youth; the number of years of healthy living is related to telomere length," says Blackburn, referring to an enzyme she helped discover in the mid 1970s.

"We don't think clocks will be turned back, but it is a question of whether we will extend our health span."

Blackburn, a professor and researcher at University of California, San Francisco, says she was surprised to receive the honour.

"As I groped in the dark for the phone and some very well spoken voice identified Sweden, Nobel Prize and committee it was a good start, but then you begin to think how many friends have a really good sense of humour."

Tips of shoelaces

"[Telomeres] are like the tips at the end of the shoelace and stop the shoelace from fraying away," says Blackburn.

"We think this is one of the things that contribute to age-related diseases. The enzyme is basically building back the tips of the shoelaces."

A problem is that there isn't much telomerase in the human body, according to the scientist.

The team did their research at the University of California, Berkeley, decades before DNA sequencing and genome project breakthroughs.

"I was just following my nose doing experiments related to my curiosity," says Blackburn. "Everybody was just curious about DNA sequencing, particularly the ends."

Manipulating telomerase can not only prevent age-related blindness and heart disease, it could let doctors prevent cancer cells from spreading, according to Blackburn.

Talented, outspoken

"[She] has made important contributions to our understanding of how cells in each new generation renew their potential to grow, develop and live for a normal lifespan," says Williamson.

"Her work on telomere regeneration is not only relevant to normal embryonic development, but also helps in our understanding of why cancer cells are able to divide without normal control.

"In the long run, her research could give rise to new approaches to treatment for cancer and other diseases."

An outspoken researcher, Blackburn was fired in 2004 from President George W Bush's Council on Bioethics in what many scientists believed was her criticism of his policy on human embryonic stem cell research.

Blackburn is currently working on tests to determine whether stress is "very bad for telomerase."

"I hope this prize will leave me lots of time to do (research); that is what I love to do," says Blackburn when asked how she plans to spend her share of the prize money.

Rewarding curiosity

Greider, who works at Johns Hopkins School of Medicine, credits her father with her decision to go into science.

"He would say 'You can do whatever you want, but you have to like whatever you do,'" she says.

Greider says the award recognises that curiosity drives some of the most important scientific research.

"We had no idea when we started this work that telomerase would be involved in cancer, but were simply curious about how chromosomes stayed intact," she says.

"Our approach shows that while you can do research that tries to answer specific questions about a disease, you can also just follow your nose."

Szostak, now a Harvard genetics professor, says the award is "the highest scientific honour, so it's great to receive that kind of recognition, again, it's great to share it with my collaborators, colleagues."

He says the research has led to a greater understanding of diseases of aging and of cancer and will hopefully lead to practical benefits.

"I think that we need a balance between basic science and applied research."

Growing list

Blackburn joins a growing list of Australian Nobel Laureats in the field of medicine and physiology.

In 2005, Professor Barry Marshall and Dr Robin Warren, received a Nobel Prize for their discovery that stomach ulcers were caused by the bacteria Helicobacter pylori.

In 1996, Professor Peter Doherty was awarded the prize for work into how the immune system recognises virus-infected cells.

Other Australians who have received the prize include Sir Howard Florey in 1945, Sir Frank Macfarlane Burnet in 1960 and Sir John Eccles in 1963.